1. Field of the Invention
The present invention relates to a micro fluid device, and in particular, to a micro fluid device with a function to accurately control change in temperature of fluid flowing through a fine channel.
2. Description of the Related Art
A micro fluid device with a fine channel has such a superior feature as to enable accurately controlling change in temperature of fluid flowing through a fine channel. And the micro fluid device is used as a device in a micro chemical process where various unit operations such as reaction, mixing, extraction and separation are performed. Unit operations by the micro fluid device require operations in which temperature of reactants is increased to a predetermined degree to accelerate reaction and then to quench to stop the reaction or solution into which solute high in temperature dissolves is quenched to accurately precipitate the solute. In particular, in the case where fine particles are produced by precipitation reaction in which solute is precipitated from solution into which the solute dissolves, it is extremely important to steeply quench the temperature of the solution.
The accurate control of temperature of fluid which flows through a fine channel requires a small heat transfer between the fine channel and the outside, an accurate change in temperature of fluid (enabling a rapid change in temperature) and a minimum possible dead space in the fine channel where the fluid may retain.
A micro fluid device provided with a mechanism for controlling temperature is described in, for example, Japanese Patent Application Laid-Open Nos. 2006-61903, 2006-159165 and 2006-326542. Japanese Patent Application Laid-Open Nos. 2006-61903 and 2006-159165 provide a device for covering the periphery of the fine channel with heat insulating materials. Japanese Patent Application Laid-Open No. 2006-326542 discloses a micro fluid device capable of precluding disturbance such as retention of fluid and temperature variation to improve quality of products.
The micro fluid devices in Japanese Patent Application Laid-Open Nos. 2006-61903 and 2006-159165 cover the periphery of the fine channel with heat insulating materials to enable reducing heat transfer between the fine channel and the outside, however, the micro fluid devices have a drawback in that they cannot rapidly stop reaction or perform precipitation reaction for producing fine particles because no device is provided to accurately change the temperature of the fluid.
Incidentally, the micro fluid device needs producing by fine processing because it has a fine channel. In this case, the micro fluid device can be more easily produced such that a plurality of units is formed by fine processing, thereafter the units are coupled together to be integrated. Japanese Patent Application Laid-Open No. 2006-326542 discloses an example in which various members forming the micro fluid device are coupled. Coupling portions are coupled with a plurality of tubes or connectors, causing a problem in that a dead space is liable to be formed at a connector portion and the temperature of fluid is liable to be scattered due to a subtle difference in length of the tubes.